G-protein-coupled receptors (GPCRs), which comprise one of the largest gene families identified in the human genome, also represent the largest number of currently used targets of therapeutic drugs. Recent work has indicated a number of intriguing observations in terms of GPCR structure, function and regulation, including existence of receptor homodimers and heterodimers, genetic identification of orphan GPCRs, novel receptor interacting proteins, clinically important polymorphisms and receptor mutations, mechanisms involved in receptor deactivation/desensitization, and receptor targeting/action in signaling microdomains. Definitive information about each of these topics is still being developed. This symposium will focus on these and related topics with an emphasis on use of new tools, e.g., bioinformatic approaches to evaluate GPCR family members, novel strategies to identify ligands active at GPCRs, and insights from nonmammalian/lower eukaryotic systems. Attendees will thus have the chance to learn and discuss new cutting edge topics regarding GPCRs.